Prosthetic joints are known which allow two prosthetic parts to swivel relative to one another, and which may be locked with respect to one another. These are generally simple uniaxial joints that may be fixed relative to one another in their respective angular position, optionally in discrete angular increments, by a locking device that blocks the two prosthetic parts. Locking or blocking devices may also be provided for motorized prosthetic devices, in particular to realize energy savings when a prosthetic part must be held in a fixed position under load.
When the lock is released and the distal prosthetic part is in an unlocked state, the part may fall downward due to gravity. This downward drop is generally not controllable, especially for non-motorized prosthetic devices. Thus, for prosthetic hands the problem arises that after the locking device is unlocked, the artificial hand drops downward without damping. This may also occur for forearm prostheses having a prosthetic joint in the elbow region; the situation is analogous for foot or lower-leg prostheses.